The xmonad-contrib (xmc) library is a set of extension modules 
contributed by xmonad hackers and users, which provide additional 
xmonad features. Examples include various layout modes (tabbed, 
spiral, three-column...), prompts, program launchers, the ability 
to manipulate windows and workspaces in various ways, alternate 
navigation modes, and much more. There are also "meta-modules" 
which make it easier to write new modules and extensions.
